I've had two kernel panics in the last few days. The log file has been the same. I've pasted the log below. I saw some chatter about this on the apple support forums, but nothing here. Anyone else having this?

Mon Dec 31 16:57:49 2007
panic(cpu 1 caller 0x0039CD77): "m_free: freeing an already freed mbuf"@/SourceCache/xnu/xnu-1228.0.2/bsd/kern/uipc_mbuf.c:2742
Backtrace, Format - Frame : Return Address (4 potential args on stack)
0x2109f978 : 0x12b0e1 (0x455670 0x2109f9ac 0x133238 0x0)
0x2109f9c8 : 0x39cd77 (0x48e03c 0x1cf57a00 0x20f6701c 0x40)
0x2109fa08 : 0x39d073 (0x1cf94900 0x8 0x2109fa58 0x1)
0x2109fa28 : 0x9dbb87 (0x1cf8ff00 0x0 0x20 0x2)
0x2109fb98 : 0x9dbec5 (0x128c22c8 0x128c4150 0xd4794 0x0)
0x2109fce8 : 0x9e720b (0x129c8004 0x0 0x29a7e3c 0x19ccc1)
0x2109fe68 : 0x9b784a (0x128c24c0 0x36a0454 0x2109fe88 0x1a136f)
0x2109feb8 : 0x9b8f3f (0xa3fc80 0xa3fc84 0xb0400000 0x0)
0x2109ff48 : 0x9b74b7 (0x30f8004 0x0 0x0 0x19ccc1)
0x2109ff78 : 0x13e987 (0x30f8494 0x30f8004 0x0 0xb0488b28)
0x2109ffc8 : 0x19e2ec (0x0 0x0 0x1a10b5 0x3717000)
Backtrace terminated-invalid frame pointer 0
Kernel loadable modules in backtrace (with dependencies):
com.apple.driver.AirPort.Atheros(300.22)@0x9b6000->0xa40fff
dependency: com.apple.iokit.IO80211Family(200.7)@0x998000
dependency: com.apple.iokit.IOPCIFamily(2.4)@0x63c000
dependency: com.apple.iokit.IONetworkingFamily(1.6.0)@0x64c000
BSD process name corresponding to current thread: kernel_task
Mac OS version:
9B18
Kernel version:
Darwin Kernel Version 9.1.0: Wed Oct 31 17:46:22 PDT 2007; root:xnu-1228.0.2~1/RELEASE_I386
System model name: MacBook2,1 (Mac-F4208CA9)